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drivers/i2c/tpm/cr50: Improve data handling and function names 

Unify the function names to be consistent throughout the driver
and improve the handling while waiting for data available and
data expected flags from the TPM.

BUG=chrome-os-partner:53336

Change-Id: I7e3912fb8d8c6ad17d1af2d2a7189bf7c0c52c8e
Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
This commit is contained in:
Duncan Laurie 2016-09-19 17:19:10 -07:00
parent 557e1a729a
commit 1241e7db55
1 changed files with 45 additions and 48 deletions
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93
src/drivers/i2c/tpm/cr50.c
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@ -189,7 +189,7 @@ static int request_locality(struct tpm_chip *chip, int loc)
} }
/* cr50 requires all 4 bytes of status register to be read */ /* cr50 requires all 4 bytes of status register to be read */
static uint8_t cr50_tis_i2c_status(struct tpm_chip *chip) static uint8_t cr50_i2c_tis_status(struct tpm_chip *chip)
{ {
uint8_t buf[4]; uint8_t buf[4];
if (cr50_i2c_read(chip, TPM_STS(chip->vendor.locality), if (cr50_i2c_read(chip, TPM_STS(chip->vendor.locality),
@ -201,7 +201,7 @@ static uint8_t cr50_tis_i2c_status(struct tpm_chip *chip)
} }
/* cr50 requires all 4 bytes of status register to be written */ /* cr50 requires all 4 bytes of status register to be written */
static void cr50_tis_i2c_ready(struct tpm_chip *chip) static void cr50_i2c_tis_ready(struct tpm_chip *chip)
{ {
uint8_t buf[4] = { TPM_STS_COMMAND_READY }; uint8_t buf[4] = { TPM_STS_COMMAND_READY };
cr50_i2c_write(chip, TPM_STS(chip->vendor.locality), buf, sizeof(buf)); cr50_i2c_write(chip, TPM_STS(chip->vendor.locality), buf, sizeof(buf));
@ -210,7 +210,7 @@ static void cr50_tis_i2c_ready(struct tpm_chip *chip)
/* cr50 uses bytes 3:2 of status register for burst count and /* cr50 uses bytes 3:2 of status register for burst count and
* all 4 bytes must be read */ * all 4 bytes must be read */
static int cr50_wait_burst_status(struct tpm_chip *chip, uint8_t mask, static int cr50_i2c_wait_burststs(struct tpm_chip *chip, uint8_t mask,
size_t *burst, int *status) size_t *burst, int *status)
{ {
uint8_t buf[4]; uint8_t buf[4];
@ -240,28 +240,26 @@ static int cr50_wait_burst_status(struct tpm_chip *chip, uint8_t mask,
return -1; return -1;
} }
static int cr50_tis_i2c_recv(struct tpm_chip *chip, uint8_t *buf, static int cr50_i2c_tis_recv(struct tpm_chip *chip, uint8_t *buf,
size_t buf_len) size_t buf_len)
{ {
size_t burstcnt, current, len, expected; size_t burstcnt, current, len, expected;
uint8_t addr = TPM_DATA_FIFO(chip->vendor.locality); uint8_t addr = TPM_DATA_FIFO(chip->vendor.locality);
uint8_t mask = TPM_STS_VALID | TPM_STS_DATA_AVAIL;
int status; int status;
int ret = -1;
if (buf_len < TPM_HEADER_SIZE) if (buf_len < TPM_HEADER_SIZE)
goto out; goto out_err;
if (cr50_wait_burst_status(chip, TPM_STS_VALID, &burstcnt, &status) < 0) if (cr50_i2c_wait_burststs(chip, mask, &burstcnt, &status) < 0) {
goto out;
if (!(status & TPM_STS_DATA_AVAIL)) {
printk(BIOS_ERR, "%s: First chunk not available\n", __func__); printk(BIOS_ERR, "%s: First chunk not available\n", __func__);
goto out; goto out_err;
} }
/* Read first chunk of burstcnt bytes */ /* Read first chunk of burstcnt bytes */
if (cr50_i2c_read(chip, addr, buf, burstcnt) != 0) { if (cr50_i2c_read(chip, addr, buf, burstcnt) != 0) {
printk(BIOS_ERR, "%s: Read failed\n", __func__); printk(BIOS_ERR, "%s: Read failed\n", __func__);
goto out; goto out_err;
} }
/* Determine expected data in the return buffer */ /* Determine expected data in the return buffer */
@ -269,45 +267,43 @@ static int cr50_tis_i2c_recv(struct tpm_chip *chip, uint8_t *buf,
if (expected > buf_len) { if (expected > buf_len) {
printk(BIOS_ERR, "%s: Too much data: %zu > %zu\n", printk(BIOS_ERR, "%s: Too much data: %zu > %zu\n",
__func__, expected, buf_len); __func__, expected, buf_len);
goto out; goto out_err;
} }
/* Now read the rest of the data */ /* Now read the rest of the data */
current = burstcnt; current = burstcnt;
while (current < expected) { while (current < expected) {
/* Read updated burst count and check status */ /* Read updated burst count and check status */
if (cr50_wait_burst_status(chip, TPM_STS_VALID, if (cr50_i2c_wait_burststs(chip, mask, &burstcnt, &status) < 0)
&burstcnt, &status) < 0) goto out_err;
goto out;
if (!(status & TPM_STS_DATA_AVAIL)) {
printk(BIOS_ERR, "%s: Data not available\n", __func__);
goto out;
}
len = min(burstcnt, expected - current); len = min(burstcnt, expected - current);
if (cr50_i2c_read(chip, addr, buf + current, len) != 0) { if (cr50_i2c_read(chip, addr, buf + current, len) != 0) {
printk(BIOS_ERR, "%s: Read failed\n", __func__); printk(BIOS_ERR, "%s: Read failed\n", __func__);
goto out; goto out_err;
} }
current += len; current += len;
} }
/* Ensure TPM is done reading data */ /* Ensure TPM is done reading data */
if (cr50_wait_burst_status(chip, TPM_STS_VALID, &burstcnt, &status) < 0) if (cr50_i2c_wait_burststs(chip, TPM_STS_VALID, &burstcnt, &status) < 0)
goto out; goto out_err;
if (status & TPM_STS_DATA_AVAIL) { if (status & TPM_STS_DATA_AVAIL) {
printk(BIOS_ERR, "%s: Data still available\n", __func__); printk(BIOS_ERR, "%s: Data still available\n", __func__);
goto out; goto out_err;
} }
ret = current; return current;
out: out_err:
return ret; /* Abort current transaction if still pending */
if (cr50_i2c_tis_status(chip) & TPM_STS_COMMAND_READY)
cr50_i2c_tis_ready(chip);
return -1;
} }
static int cr50_tis_i2c_send(struct tpm_chip *chip, uint8_t *buf, size_t len) static int cr50_i2c_tis_send(struct tpm_chip *chip, uint8_t *buf, size_t len)
{ {
int status; int status;
size_t burstcnt, limit, sent = 0; size_t burstcnt, limit, sent = 0;
@ -317,25 +313,26 @@ static int cr50_tis_i2c_send(struct tpm_chip *chip, uint8_t *buf, size_t len)
stopwatch_init_msecs_expire(&sw, CR50_TIMEOUT_LONG_MS); stopwatch_init_msecs_expire(&sw, CR50_TIMEOUT_LONG_MS);
/* Wait until TPM is ready for a command */ /* Wait until TPM is ready for a command */
while (!(cr50_tis_i2c_status(chip) & TPM_STS_COMMAND_READY)) { while (!(cr50_i2c_tis_status(chip) & TPM_STS_COMMAND_READY)) {
if (stopwatch_expired(&sw)) { if (stopwatch_expired(&sw)) {
printk(BIOS_ERR, "%s: Command ready timeout\n", printk(BIOS_ERR, "%s: Command ready timeout\n",
__func__); __func__);
return -1; return -1;
} }
cr50_tis_i2c_ready(chip); cr50_i2c_tis_ready(chip);
} }
while (len > 0) { while (len > 0) {
uint8_t mask = TPM_STS_VALID;
/* Wait for data if this is not the first chunk */
if (sent > 0)
mask |= TPM_STS_DATA_EXPECT;
/* Read burst count and check status */ /* Read burst count and check status */
if (cr50_wait_burst_status(chip, TPM_STS_VALID, if (cr50_i2c_wait_burststs(chip, mask, &burstcnt, &status) < 0)
&burstcnt, &status) < 0) goto out_err;
goto out;
if (sent > 0 && !(status & TPM_STS_DATA_EXPECT)) {
printk(BIOS_ERR, "%s: Data not expected\n", __func__);
goto out;
}
/* Use burstcnt - 1 to account for the address byte /* Use burstcnt - 1 to account for the address byte
* that is inserted by cr50_i2c_write() */ * that is inserted by cr50_i2c_write() */
@ -343,7 +340,7 @@ static int cr50_tis_i2c_send(struct tpm_chip *chip, uint8_t *buf, size_t len)
if (cr50_i2c_write(chip, TPM_DATA_FIFO(chip->vendor.locality), if (cr50_i2c_write(chip, TPM_DATA_FIFO(chip->vendor.locality),
&buf[sent], limit) != 0) { &buf[sent], limit) != 0) {
printk(BIOS_ERR, "%s: Write failed\n", __func__); printk(BIOS_ERR, "%s: Write failed\n", __func__);
goto out; goto out_err;
} }
sent += limit; sent += limit;
@ -351,25 +348,25 @@ static int cr50_tis_i2c_send(struct tpm_chip *chip, uint8_t *buf, size_t len)
} }
/* Ensure TPM is not expecting more data */ /* Ensure TPM is not expecting more data */
if (cr50_wait_burst_status(chip, TPM_STS_VALID, &burstcnt, &status) < 0) if (cr50_i2c_wait_burststs(chip, TPM_STS_VALID, &burstcnt, &status) < 0)
goto out; goto out_err;
if (status & TPM_STS_DATA_EXPECT) { if (status & TPM_STS_DATA_EXPECT) {
printk(BIOS_ERR, "%s: Data still expected\n", __func__); printk(BIOS_ERR, "%s: Data still expected\n", __func__);
goto out; goto out_err;
} }
/* Start the TPM command */ /* Start the TPM command */
if (cr50_i2c_write(chip, TPM_STS(chip->vendor.locality), tpm_go, if (cr50_i2c_write(chip, TPM_STS(chip->vendor.locality), tpm_go,
sizeof(tpm_go)) < 0) { sizeof(tpm_go)) < 0) {
printk(BIOS_ERR, "%s: Start command failed\n", __func__); printk(BIOS_ERR, "%s: Start command failed\n", __func__);
goto out; goto out_err;
} }
return sent; return sent;
out: out_err:
/* Abort current transaction if still pending */ /* Abort current transaction if still pending */
if (cr50_tis_i2c_status(chip) & TPM_STS_COMMAND_READY) if (cr50_i2c_tis_status(chip) & TPM_STS_COMMAND_READY)
cr50_tis_i2c_ready(chip); cr50_i2c_tis_ready(chip);
return -1; return -1;
} }
@ -379,10 +376,10 @@ static void cr50_vendor_init(struct tpm_chip *chip)
chip->vendor.req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID; chip->vendor.req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID;
chip->vendor.req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID; chip->vendor.req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID;
chip->vendor.req_canceled = TPM_STS_COMMAND_READY; chip->vendor.req_canceled = TPM_STS_COMMAND_READY;
chip->vendor.status = &cr50_tis_i2c_status; chip->vendor.status = &cr50_i2c_tis_status;
chip->vendor.recv = &cr50_tis_i2c_recv; chip->vendor.recv = &cr50_i2c_tis_recv;
chip->vendor.send = &cr50_tis_i2c_send; chip->vendor.send = &cr50_i2c_tis_send;
chip->vendor.cancel = &cr50_tis_i2c_ready; chip->vendor.cancel = &cr50_i2c_tis_ready;
} }
int tpm_vendor_probe(unsigned bus, uint32_t addr) int tpm_vendor_probe(unsigned bus, uint32_t addr)